• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.217-219
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• 2006

4G mobile networks are expected to support various multimedia services over IP networks and also satisfy high spectral efficiency requirement. In cellular systems including 4G networks, hotspot cells can occur when available wireless resources at some location are not enough to sustain the needs of users. The hotspot cell can potentially lead to blocked and dropped calls, which can deteriorate the service quality for users. In a 4G mobile network, a band of users enjoying multimedia services can move around, which may generate heavy flows of traffic load. This situation can generate the hotspot cell which has a short life span of only a few minutes. In this paper, we propose a handover-based scheme which can effectively manage hotspot cells in 4G mobile networks. With the scheme, the current serving cell can recognize the load status of the target cell in advance before handover execution. Adaptive handover time control according to the amount of traffic load of cells can effectively and flexibly manage the hotspot cell in the network. And, through our hotspot cell management scheme, acceptable service quality can be supported as users continuously maintain connections with the network. In the simulation results, we find that our scheme generates smaller number of hotspot cells and supports higher service quality than the compared schemes.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.2 no.1
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• pp.75-90
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• 1996

This experiment was designed to study the antitumor effects and Activity of Natural Killer Cell of semen Tiglii plus Rhizoma Rhei. The cytotoxic and antitumor effects were evaluated on human cell lines(A549, Caki-1, LL2, Sarcoma 180, NIH/3T3) after exposure to prebrewed Semen Tiglii plus Rhizoma Rhei water extract 0.1, 0.2, 0.4, 0.8, 1.6mg/ml using in MTT assay, LDH, colony forming efficency and SRB assay which were regarded as a valuable method for cytotoxic and antitumor effects of unknown compound on tumor cell lines. The results obtained in this studies were as follows. 1. From the result of MTT assay, the cytotoxicity of ST(生巴豆霜), ST+RR(生巴豆霜加大黃) were concentration-dependently increased in both group of the ST and ST+RR, the cytotoxicity of ST+RR(生巴豆霜加大黃) was similar to that of ST(生巴豆霜). 2. From the result of LDH, the cytotoxicity of ST, ST +RR were concentrati -on-dependently increased in both group of the ST and ST+RR, the cytotoxicity of ST+RR was similar to that of ST. 3. The antitumor effect on A549 tumor cell from the result of colony forming efficiency showed the inhibitory effect on the growth in both group of the ST and ST+RR, the inhibitory effect on growth was low slightly in the ST+RR. 4. From the result of SRB assay, the antitumor effect on caki-1 tumor cell of ST, ST+RR showed the inhibitory effect on the growth in both group of the ST and ST+RR, the antitumor effect of ST+RR was similar to that of ST. 5. Median survival time and increased life span were increased slightly in both group of the ST and ST+RR. 6. The inhibitory effect on the growth of Sarcoma 180 and Lewis lung carcinoma tumor cell were increased slightly in both group of the ST and ST+RR. 7. The activity of NK cell was increased in the ST+RR.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.132-139
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• 2020

Solid oxide fuel cells (SOFCs) are among one of the promising technologies for efficient and clean energy. SOFCs offer several advantages over other types of fuel cells under relatively high temperatures (600℃ to 800℃). However, the thermal behavior of SOFC stacks at high operating temperatures is a serious issue in SOFC development because it can be associated with detrimental thermal stresses on the life span of the stacks. The thermal behavior of SOFC stacks can be influenced by operating or material properties. Therefore, this work aims to investigate the effects of the thermal conductivity of each component (anode, cathode, and electrolyte) on the thermal behavior of samarium-doped ceria-based SOFCs at intermediate temperatures. Computational fluid dynamics is used to simulate SOFC operation at 600℃. The temperature distributions and gradients of a single cell at 0.7 V under different thermal conductivity values are analyzed and discussed to determine their relationship. Simulations reveal that the influence of thermal conductivity is more remarkable for the anode and electrolyte than for the cathode. Increasing the thermal conductivity of the anode by 50% results in a 23% drop in the maximum thermal gradients. The results for the electrolyte are subtle, with a ~67% reduction in thermal conductivity that only results in an 8% reduction in the maximum temperature gradient. The effect of thermal conductivity on temperature gradient is important because it can be used to predict thermal stress generation.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.16-22
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• 2000

These studies were designed to determine the potential cytotoxic activity of MeOH extracts of 65 crude drugs against leukemia L1210 and $P388D_1$, cell line in vitro, of which 25 samples were selected. The n-BuOH extracts of 25 samples were measured using the same method and nine were selected. These samples were measured for the potential antitumor activity against $P388D_1$, for life span in vivo, and against sarcoma 180 for tumor weight. On the basis of results, Notoginseng Radix, Anemarrhenae Rhizoma, Albizziae Cortex, Portulacae Herba, Bupleuri Radix were evaluated the effective plant on the antitumor activity. In addition, the mixture of Notoginseng Radix and Albizziae Cortex was evaluated to enhance the antitumor activity in vivo.

• YAKHAK HOEJI
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• v.30 no.4
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• pp.193-197
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• 1986

A strongly cytotoxic fraction (Fc-2, ED50=0.0003$\mu\textrm{g}$/ml) against L1210 cell was obtained from the root, seed and fruit of Trichosanthes kirilowii. Administration of Fc-2 prolonged the life span of the BDF1 mice bearing L1210 and the ICR mice bearing S-180 by 135%, and 130%, respectively. The Fc-2 affected L1210 cells were enlarged in their diameters two or three times in comparison with the untreated ones. When 20mg/kg of Fc-2 was administered, intraperitoneally, all the mice were killed.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.479-482
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• 2003

Radiosensitizing and antitumor effects of hot water extract derived from the seed of Benincasae hispida were investigated. The extract showed maximum survival rate of 21% at 0.1 g/kg against L1210 cells implanted in BDF1 mice. Radiosensitivity of human tumor cell line was evaluated through sulforhodamine assay. Inhibition rate of SK-OV-3 cells after 5 Gy radiation by Benincasae hispida seed extract at 2 mg/mL was 86%.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.296-301
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• 1987

Polyamines of Korean red ginseng were extracted with 5% trichloroacetic acid and purified by ion exchange chromatography using Dowex-50Wx8 resin. Four spots having R$_f$ values of 0.19, 0.28, 0.35, and 0.45 were detected. It was observed under microscopy that those polyamines stimulated the growth and differentiation of chicken embryonic muscle cell. The development of muscle cells from the stage of myoblast to that of myotube was found to be enhanced by those polyamines. It was also observed that those polyamines most likely lengthened, the life-span of the cultured chicken embryonic skeletal muscle cells.

• Development and Reproduction
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• v.21 no.4
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• pp.449-456
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• 2017

The germline stem cells of the Drosophila ovary continuously produce eggs throughout the life-span. Intricate regulation of stemness and differentiation is critical to this continuous production. The translational regulator Nos is an intrinsic factor that is required for maintenance of stemness in germline stem cells. Nos expression is reduced in differentiating cells at the post-transcriptional level by diverse translational regulators. However, molecular mechanisms underlying Nos repression are not completely understood. Through three distinct protein-protein interaction experiments, we identified specific molecular interactions between translational regulators involved in Nos repression. Our findings suggest a model in which protein complexes assemble on the 3' untranslated region of Nos mRNA in order to regulate Nos expression at the post-transcriptional level.

• Journal of Pharmacopuncture
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• v.13 no.1
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• pp.5-14
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• 2010

Objectives : This study was performed to examine the anticancer effect of mountain ginseng Pharmacopuncture(MGP) to the nude mouse of lung carcinoma induced by NCI-H460 human nonsmall lung cancer cells. Methods : Human lung cancer (NCI-H460) cells were cultured and applied to evaluate anti-tumor activity in nude mice. After confirmed tumor growth in mice, MGP was treated per 0.1ml/kg dose to intraperitoneal and intravenous injection everyday for four weeks. And checked the changes in body weights, tumor volume, mean survival time and percent, increase in life span, histo-pathological findings, organ weights, and blood chemistry levels. Results : The results of in vivo study showed that MGP may have potential as growth inhibitor of solid tumor induced NCI-H460 without marked side effects. MGP inhibited dosage-dependently the growth of NCI-H460 cell-transplanted solid tumor compared with the control group. And mean survival time of MGP treated group was prolonged comparing with control group. Generally the group of intravenous injection is more effective than intraperitoneal injection. Conclusion : These results were suggested that MGP may be a useful anticancer agent for therapy of human lung cancer. And follow study need for the certain evidence.

• The Journal of Internal Korean Medicine
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• v.22 no.1
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• pp.73-78
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• 2001

After examining and analysing the medicinal herbs of fifty-three experimental papers, we studied their effects on immediate tumors in specific cancers. We did not study the influence on the life span of general cancerous cells. We looked to see if the combined usage of medicinal herbs and anticancer agents inhibited the tumor cell's growth. The serum test and blood cell count test showed if the medicinal herbs inhibited the side effects of the anticancer agent. The test showed that more than 80 percent of used medicinal herbs, brought anticancer activities. However, anticancer experimental studies using medicinal herbs have draw-backs. First, it is difficult to choose a prescription using the standards of Oriental Medicine because we are testing a mouse not a man. Second, because we only observed the indirect effect on the whole physiological regulation caused by the synergic effects of the complex prescription, we are not able to understand the detailed mechanism of the herbs. Therefore; if the anticancer effect of the herbs is proved by the experiment, we need to research the concrete medical action of medicinal herbs and the immunological analysis of herbal medicines on the body.